1. Field of the Invention
This invention relates to a furnace for providing heated air to an interior comfort space, and is more particularly directed to a turn in place mounting for retaining a transformer to the shelf from which a furnace air blower is suspended.
2. Description of the Prior Art
In conventional gas-fired forced air furnaces a thermostat senses the temperature in the comfort zone relative to a predetermined set point temperature. When the comfort zone temperature is below the set point, the thermostat closes to supply thermostat ac power to the furnace as a call for heat. This initiates a sequence of events that ultimately causes the furnace to activate. An inducer motor is enabled, which in turn causes the flow of combustion air across the burners and through a heat exchanger, after which a gas valve is actuated to supply gas to the gas burners. At the same time, an ignition device is actuated to light the burners. A flame sensor then proves burner ignition and sends power to a blower delay timer. After a predetermined blower delay time, which varies with furnace design, the furnace blower is actuated. The blower moves circulated room air from a return air duct through the furnace heat exchanger to accept heat from the heated combustion products (carbon dioxide and water vapor) produced by the gas burners. The heated circulated air then goes into a hot air plenum and is distributed through hot air duct-work back to the comfort zone. When the comfort zone air is warmed sufficiently to reach the thermostat set point, the thermostat terminates the call for heat. When this happens the blower and burners go through a shut off sequence and the furnace awaits the next call for heat.
The air blower is suspended beneath a shelf located in the furnace and, in the prior art, the transformer was mounted either directly on the blower using a pair of screws or directly to a metal control box. The transformer steps down line voltage (115 VAC) to control voltage (24 VAC). Manufacturing the hardware necessary to secure the transformer had the disadvantage of being relatively complicated. Furthermore, installation and servicing of the transformer requiring two mounting screws proved difficult as two hands had to be used. The transformer had to be held in place with one hand while the other hand was securing it, via the first screw, to the mounting.
In the present invention, the transformer is mounted inside an enclosed housing that holds the air blower. Both the transformer and blower are suspended from an interior furnace wall. Multiple brackets are positioned inside the housing at varying distances from a fastenable bracket. Depending on the size of the transformer, a first flange on the transformer engages one of the multiple brackets whereby the transformer is rotatably supported. A second flange mounted on the transformer engages the fastenable support bracket. Transformer placement on both brackets fully supports the transformer and can be performed with one hand. The transformer will rest on the brackets for a sufficient duration to allow a single screw placed through a hole associated with the fastenable bracket to lock it in place.
The portion of the wall from which the transformer is mounted is formed out of the plane of the wall, away from the housing so that any condensate will run off this portion onto the rest of the wall and condensate will not percolate through the screw-hole onto the transformer.
In addition, because the mounting brackets are located within the blower housing, only a single screw protrudes outside of the housing. Thus drainage tubes may pass freely across the outside of the housing wall without interference from the mounting apparatus.